1. Field of the Invention
This invention is directed to conveyors for feeding sand molds for metal casting from a forming machine to a metal pouring station. The method provides a method and apparatus for automatically and continually feeding prepared sand molds from multiple forming machines to a common pouring station using walking beam-type mold conveyors.
2. Discussion of Related Art
Molded metal castings are commonly manufactured at foundries through a matchplate molding technique which employs green sand molds comprised of prepared sand and additives which are compressed around cope and drag patterns mounted on opposite sides of a matchplate. The sand mold is thus formed in upper and lower matching portions, an upper cope mold, and a lower drag mold. The cope mold is formed in a separate cope flask which is filled with prepared sand and compacted onto the matchplate. The matchplate is then removed leaving an indentation in the cope mold of the desired shape for the upper portion of the casting. Simultaneously, the drag mold is formed in a separate drag flask. Usually the matchplate is in the form of a planar member with the pattern for the cope mold on one side and the pattern for the drag mold on the other. After the cope and drag molds have been formed, they are placed together to form a unitary mold having an interior cavity of the desired shape. The cavity can then be filled with molten metal through an inlet or “sprue” provided in the cope mold to create the desired casting. Such a system is disclosed in U.S. Pat. No. 5,022,212, issued to Hunter, herein incorporated by reference.
As with many volume sensitive production operations, manufacturers are required to automate the manufacturing process in order to remain competitive. Foundries engaging in the casting of metal objects through the use of green sand molds are not immune to this reality. It is common in today's marketplace, for the machine which produces the sand molds to be connected to a machine which fills the sand mold with molten metal, which in turn is connected to a machine for cooling the molten metal into a solid casting, which in turn is connected to a machine for removing the sand mold and revealing the casting for harvest. Such a system is disclosed in U.S. Pat. No. 4,589,467, issued to Hunter, herein incorporated by reference.
U.S. Pat. No. 7,637,303, issued to Hunter, herein incorporated by reference, discloses a walking-beam conveyor for transporting molds from multiple forming stations to a common pouring and/or cooling station. The walking-beam conveyor provides advantages, but may not always be able to be retrofitted into existing machinery, particularly from different manufacturers.
There is a continuing need for an improved conveyor system for transporting sand molds from the machine that produces the sand mold to, for example, the carousel conveyor.